The invention pertains to a process for the video recording of field illuminated by a lamp, especially a surgical lamp, where at least one light beam for illuminating the field emerges in the direction of a predetermined housing axis from at least one light exit area of a lamp housing. The invention also pertains to a corresponding device.
A process for transmitting video signals and an image transmission system for surgical lamps is known from DE 195-23,377 C1. For this purpose, a surgical lamp is equipped with a video camera near the lamp housing to produce external images of the surgical field in association with a monitor screen and a control device. An adjustable suspension device is used to connect the lamp housing to a hanger bracket on the ceiling of the operating room.
FIG. 1 of this DE reference shows a lamp in which the video camera is mounted off-center.
The problem with a setup such as this is that any adjustment of the surgical lamp relative to the object being recorded, i.e., the surgical field, also results in a change in the orientation of the image with respect to the surgical field, i.e., a change in the appearance of the field being shown. As a result, it is possible that the image being reproduced will be appear to the surgeon to be displaced or rotated with respect to the original view of the surgical field.
An image transmission system for a video camera in conjunction with a surgical lamp and a control device with a monitor screen and a control unit is also known from EP 0,989,744 A1, which system has at least one image sensor in the camera, which is mounted in an adjustable support, where the control unit actuates at least one drive device to position at least the image sensor relative to the object being recorded. The video camera in this case is connected to the body of a surgical lamp, which is held in a stationary mount by means of an adjustable suspension. At least the image sensor of the video camera is supported with freedom to rotate around its optical axis, and the video camera is mounted in a swivel bearing located in the body of the surgical lamp, the axis of the swivel bearing extending approximately perpendicular parallel to the optical axis of the video camera.
The problem here is that only a frontal view in the direction in which the object being recorded is illuminated is possible.
When the camera, especially a video camera, is to be attached to a lamp, such as a surgical lamp, it can be necessary or desirable to mount the camera outside the optical axis of this lamp. In this case, the optical axis of the camera must be at an angle to the optical axis of the lamp so that it can illuminate the center of the field. We speak in this case of a parallax between the two objects.